What is the Difference Between
Solid Bronze and Cold Cast Bronze?
We believe everyone should be able to collect and enjoy fine art. So for the first time in over 25 years of providing museum quality solid bronze sculpture to our patrons we are now offering a spectacular collection of sculptures that we are casting in bonded bronze resin. This high quality bonding process gives us the ability to offer a collection of sculptures with the look and feel of solid bronze to a much wider audience at prices more collectors can afford.
There is difference between bonded bronze (cold-cast bronze), and solid bronze (hot-cast bronze). Understand that in either of these two materials, the casts (the sculpture made out of the mold) are made using the same mold; which is taken from the original clay sculpture. So that the sculpture is exactly the same, but made in different materials.
Cold-Cast Bronze or Bonded Bronze as it is sometimes called, is actually made of an epoxy or resin. Real bronze powder is used to achieve the bronze appearance. Marble dust can also be added to the resin to achieve a marble look, hence bonded stone. The technique used for making items in cold cast bronze, involves blending bronze powder with epoxy designer resin to produce a material which is applied to the interior of a silicone mold. The mold is then filled with a blend of resin and bronze metal powder which are then left to set. The finished item has the look, cold feel and sometimes (although not always) the weight of a solid bronze sculpture. The cold cast bronze and/or stone process that we use is able to produce a museum quality sculpture which looks and feel like bronze, silver or marble at a lower cost of a solid bronze.
Hot-Cast Bronze is actually Bronze - essentially copper and tin; the tin not exceeding 11%. Other metals may be added to give different characteristics to the solid metal.
The making of a Hot-Cast Bronze is a complex and time consuming process, and specific technical expertise is needed to accomplish the task of making a bronze. The most known and used process for making sculpture is called the "Lost Wax" Process:
A 1/4 inch hollow wax of the sculpture is made from the rubber mold capturing all the details . The wax is layered inside and outside with seven coats of a ceramic shell material; which harden around the hollow wax sculpture. The ceramic shell is then placed into an oven and the wax sculpture is melted out. This leaves a 1/4" space once occupied by the wax. Molten bronze is then poured into this space in the ceramic shell, and is set aside to cool and harden. The ceramic shell is broken off the bronze and the finishing process begins; cleaning and chaising the bronze sculpture. The finished bronze is then ready for patination. A torch is used to heat up the surface of the sculpture, minerals deluted in water are brushed onto the heated surface creating a wide range of colors and patterns. This is just a brief explaination of the process and to really appreciate the process, one should visit your local sculpture foundry.
After comprehending the processes above, one can understand why the cost for a solid bronze sculpture is much greater than that of a cold-cast bronze. Solid bronze is also the most durable and beautiful material to use and it lasts the test of time. Other metals generally used for sculpture are Stainless Steel, Aluminium, Silver.
Cold-Cast or Bonded Bronze can also be collectable and allows a wider range of clients. It is also very durable, and larger sculptures can be created at a fraction of the cost of bronze is out of the question.
In conclusion, the choice of materials is yours to make. Your investment in a masterpiece sculpture by Keith Allen Johnson cast in (solid bronze) or (cold cast bronze) is a true museum quality art treasure that will be enjoyed for generations!